1. Field of the Invention
This invention relates to an inlet tube for delivering air to the air cleaner system of an automotive engine.
2. Disclosure Information
Air inlet systems for automotive and industrial vehicles have used a variety of configurations. U.S. Pat. No. 4,077,787 to Akado et al., U.S. Pat. No. 4,440,555 to Chichester, and U.S. Pat. No. 4,699,639 to Gieseke et al. disclose systems for drawing intake air from within the engine compartment of a vehicle itself. Such systems suffer from a deficiency insofar that inducted air will be heated above the ambient temperature by the engine's heat prior to being drawn into the air cleaner system. This is undesirable because it has been determined that the formation of oxides of nitrogen, a regulated automotive exhaust emission constituent, is exacerbated by elevated air intake temperatures. Accordingly, it is one object of the present invention to provide an engine air cleaner inlet tube which allows air to be drawn from outside the engine compartment of an automotive vehicle, but without imposing unnecessary flow restriction upon the passage of engine inlet air through the tube.
U.S. Pat. No. 4,778,029 to Thornburgh, and U.S. Pat. No. 4,790,864 to Kostun disclose automotive air inlet devices incorporating venturi tubes for the purpose of mitigating engine air induction noise. Note that the devices shown in the '029 and '864 patents do not include any type of airflow entry structure for introducing air into the vicinity of the venturi.
U.S. Pat. No. 4,420,057 to Omote et al. discloses an air induction structure for an automotive vehicle which, although drawing air from outside the vehicle through its radiator grill, requires the air to pass immediately through a flattened section having a 90.degree. bend. The restriction caused by this flattened section at higher airflow rates will be considerable.
It is an object of the present invention to provide an engine air cleaner inlet which picks up air from outside the engine compartment of the vehicle and allows the air to flow into the air cleaner system of the vehicle with minimum flow restriction.
It is another object of the present invention to provide an engine air cleaner inlet tube which may be oriented in any one of a plurality of discharge angles, as defined herein, without significantly changing the air inlet restriction.
Other objects, features and advantages of the present invention will become apparent to the reader of this specification.